Means for controlling compression in engines



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June 2, 1936. O SNYDER I 2,042,969

MEANS FOR CONTROLLING COMPRESSION IN ENGINES Filed Sept. 5, 1953 Patented June 2 1 .936

PATENT OFFICE 2,042,9e MEANsTFoR. coN'moL mG COMPRESSION I IN ENGINES; I James 0. Snyder, Indianapolis; Ind. A mmfiimsemembeI 5, 1933, Serial No. 688,231

" 'rclaim. (o1. its-:48)

The object of this invention is to provide means whereby the compression in aninternal combus tion engine may be controlled so that, when starting, the engine will. operate on low; compression but can be adjusted to compress. to successively higher degrees as the speed ofgthe en gine or the demands upon the same increase.v

The invention also has for its object the provision of a compression chamber whichis of greater volume or cubic content than the compression,

chambers now ordinarily provided and includes means whereby the volume of the compression chamber may be reduced and the degree of com-* pression accordingly raised as thenecessities or desires of the operator may require or suggest. The stated objects and other objects, which will appear incidentally during the course of the following description, are attainedin such a struc-' ture as is illustrated in the accompanying drawing, and the invention resides in certain novel features which will be particularly pointed out in the appended claim.

In the drawing,

Figure 1 is a diametrical section through 2. cylinder head and the upper end of a cylinder of an internal combustion engine having my present invention applied thereto.

Figure 2 is a bottom plan View of the cylinder head, the line II in this figure indicating the plane of the section shown in Figure 1.

Figure 3 is a detail elevation showing a plurality of cylinders having the invention applied thereto for simultaneous adjustment.

In the drawing, the reference numeral I indicates a cylinder head, the numeral 2 indicates the upper end of a cylinder and the numeral 3 indicates the upper end of a piston working in the cylinder, the cylinder having a surrounding water space, indicated at 4, and the cylinder head being of a hollow construction so as to provide a water jacket 5. In the underside of the cylinder head there is formed a recess or chamber 6 which constitutes a compression and combustion chamber, said chamber having. a substantially circular portion arranged directly over the cylinder and adapted to accommodate the end of the piston when the latter is at the upper end of its stroke. The compression chamber is also formed with a lateral extension, shown at I, which extends over the inlet and outlet valves'of the engine, one of said valves being shown in dotted lines at 8, and said valves operating in the usual manner in order that the fuel and spent gases may follow the proper courses. The lateral extension or enlargement I is of greater depth than the circular portion 6 so as to increase the 031198101. ty of the compression and combustionchamber; and the upperwall or ceiling of the extension is inclined downwardly so as to gradually merge into the upper wall or ceiling of the circular portion 6. It will also be noted, upon reference to the drawing, thatthe width of the lateral exten: sion gradually decreases toward the center of the circular portion 6. Within the water space of the'cylinder head, there is formed a web 9 which is preferably of circular crossse'ction and has ,acentral opening or passage therethrough in which is slidably received the stem III of a disk valve I I adapted to engage the valve seat I2 formed in the upper wall or ceiling of the; extension chamber I. The valve seat I2 is defined at the lower end of a pocket or tubular portion of the web, which pocket is preferably alined with the usual inlet valve, and the upper extremity oij said web is also constructed to define a pocket I3 receiving packing I4, to prevent leakage of gases around the valve stem, and an expansion spring I5 which rests upon the packing and bears against the underside of an abutment I6 on the valve stem near the upper end of the latter. Integral with the web 9 and extending laterally therefrom within the water space of the cylinder head there is a chamber or reservoir I! which communicates with the extension chamber 1 and the lower tubular end of the web 9 through a port I8, as clearly shown in Figure 1. i

It will now be understood that if the valve ll be unseated when fuel mixture is passing into the combustion and compression chamber, the charge will not -be confined below the valve seat but will pass upwardly and escape through the port I8 into the reservoir I? and, as a result, the compression of the charge will be low. If the valve be permitted to approach its seat, the flow of the fuel charge through the port I8 will be more or less restricted and retarded, and if the valve be seated none of the charge can pass to the reservoir II so that the entire charge will be confined within the chamber 6 and its lateral extension 'I and, consequently, the compression stroke of the piston will compress the charge to a high degree. The operator, by properly adjusting the valve, may, accordingly, regulate the compression in the engine, and experience has demonstrated that the speed of the engine can be very quickly accelerated by merely adjusting the valve for a higher degree of compression and the acceleration will be accomplished without any increased consumption of fuel and, consequently, as compared with previous engines, the consumption of fuel is greatly economized.

The spring l5 acts constantly to hold the valve l I on its seat and there is provided means whereby the valve may be adjusted so as to regulate the degree of compression, as required. To this end, a bracket or lug I9 is provided upon the top of the cylinder head and a rock shaft 20 is journaled in and extends through this lug. An eccentric 2! is secured on one end of this rock shaft and bears upon the end of the valve stem, as clearly shown in Figure 1, so that if the shaft be rocked to present the high part of the eccentric to the valve stem, the valve will be unseated, and if the low part of the eccentric be presented to the valve stem, the valve will be seated under the action of the spring l6. A crank arm 22 is secured to the end of the rock shaft 20 remote from the eccentric and the crank arms of the several cylinders are connected by a link or connecting rod 23, as clearly shown in Figure 3. A link 24 is pivoted to the rear end of the connecting rod and extends to the instrument board in the vehicle so that it may be easily manipulated by the chauffeur or other operator.

It should be understood that the valves may be linked to and operated by a speed governor so as to automatically attain high compression as the speed of the engine increases.

In casting the cylinder heads, it frequently happens that some slight irregularities or dif ferences occur in the dimensions of the compression chambers. To compensate for this condition and to attain uniformity in all the cylinders of any one engine, a plug 25 is mounted in a web 26 which is formed in each cylinder head at the lower side of the same and contains a threaded opening 21 to receive the plug. A cap screw 28 is fitted in the outer end of the opening so as to cover the plug 25 and prevent the access of any dirt thereto and also to present difficulties to any unauthorized persons who may attempt to tamper with the engine. Obviously, if the plug be adjusted inwardly, the capacity of the compression chamber will be decreased. Outward adjustment of the plug will increase the capacity of the chamber. The spark plug opening is shown at 29 in Figure 2. The compression valve is disposed at one side of the spark plug, which may be mounted in the cylinder head in the usual manner, and project into the lateral extension 1 of the compression chamber or operate within a pocket provided therefor.

From the foregoing description, taken in connection with the accompanying drawing, it will be seen that I have provided an exceedingly simple device whereby the compression in an engine may be easily controlled, and an ordinary engine, at a slight cost, converted from a low compression engine into a high compression engine. While the compression and combustion chamber has been enlarged, the cylinder head has been kept to approximately its original normal size, and it has been found unnecessary to alter the external design of the cylinder head so that the invention may be applied to existing engines at a slight cost.

Having thus described the invention, I claim:

In an internal combustion engine, a cylinder head having a combustion chamber in its underside, a tubular web extending through the head and having a pocket in its lower end opening into the combustion chamber, a downwardly opening valve arranged to seat in said pocket, means for unseating the valve, and a reservoir formed in 3 said web and extending laterally therefrom within the head and communicating with said pocket through a port in the web.

JAMES O. SNYDER. 

